Viral diseases are responsible for both global pandemics and yearly seasonal epidemics such as influenza. Outbreaks may be characterized by potentiated virulence and may occur suddenly, resulting in serious mortalities. Importantly, viral diseases are not limited to humans. For example, influenza also affects livestock and birds, which may have significant impact on food supply in addition to increasing the risk of transmission to humans. Exemplary conditions related to viral infection include, for example, influenza, small pox, encephalitis, West Nile disease, yellow fever, Dengue fever, hepatitis, human immunodeficiency, polio, and Coxsackie.
The genome of the influenza A virus has an RNA-dependent RNA polymerase, which is a heterotrimeric complex of three subunits (PA, PB1 and PB2). The RNA polymerase catalyzes viral RNA transcription and replication. Because transcription and replication of the virus depends on the activity of RNA polymerase, this enzyme has become of interest as a target for development of new anti-viral compounds, especially in the wake of the recent emergence of drug resistant viruses.